1 Instructions to code your own VLC Lua scripts and extensions
7 Lua documentation is available on http://www.lua.org/ . The reference manual
8 is very useful: http://www.lua.org/manual/5.1/ .
10 All the Lua standard libraries are available.
16 Several types of VLC Lua scripts can currently be coded:
17 * Playlist and websites parsers (see playlist/README.txt)
18 * Art fetchers (see meta/README.txt)
19 * Interfaces (see intf/README.txt)
20 * Extensions (see extensions/README.txt)
21 * Services Discovery (see sd/README.txt)
23 Lua scripts are tried in alphabetical order in the user's VLC config
24 directory lua/{playlist,meta,intf}/ subdirectory on Windows and Mac OS X or
25 in the user's local share directory (~/.local/share/vlc/lua/... on linux),
26 then in the global VLC lua/{playlist,meta,intf}/ directory.
29 3 - VLC specific Lua modules
30 ============================
32 All VLC specifics modules are in the "vlc" object. For example, if you want
33 to use the "info" function of the "msg" VLC specific Lua module:
34 vlc.msg.info( "This is an info message and will be displayed in the console" )
36 Note: availability of the different VLC specific Lua modules depends on
37 the type of VLC Lua script your are in.
41 config.get( name ): Get the VLC configuration option "name"'s value.
42 config.set( name, value ): Set the VLC configuration option "name"'s value.
43 config.datadir(): Get the VLC data directory.
44 config.userdatadir(): Get the user's VLC data directory.
45 config.homedir(): Get the user's home directory.
46 config.configdir(): Get the user's VLC config directory.
47 config.cachedir(): Get the user's VLC cache directory.
49 config.datadir_list( name ): Get the list of possible data directories in
50 order of priority, appended by "name"
54 local d = vlc.dialog( "My VLC Extension" ): Create a new UI dialog, with a human-readable title: "My VLC Extension"
55 d:show(): Show this dialog.
56 d:hide(): Hide (but not close) this dialog.
57 d:delete(): Close and delete this dialog.
58 d:set_title( title ): set the title of this dialog.
59 d:update(): Update the dialog immediately (don't wait for the current function to return)
60 d:del_widget( widget ): Delete 'widget'. It disappears from the dialog and repositioning may occur.
62 In the following functions, you can always add some optional parameters: col, row, col_span, row_span, width, height.
63 They define the position of a widget in the dialog:
64 - row, col are the absolute positions on a grid of widgets. First row, col are 1.
65 - row_span, col_span represent the relative size of a widget on the grid. A widget with col_span = 4 will be displayed as wide as 4 widgets of col_span = 1.
66 - width and height are size hints (in pixels) but may be discarded by the GUI module
67 Example: w = d:add_label( "My Label", 2, 3, 4, 5 ) will create a label at row 3, col 2, with a relative width of 4, height of 5.
69 d:add_button( text, func, ... ): Create a button with caption "text" (string). When clicked, call function "func". func is a function reference.
70 d:add_label( text, ... ): Create a text label with caption "text" (string).
71 d:add_html( text, ... ): Create a rich text label with caption "text" (string), that supports basic HTML formatting (such as <i> or <h1> for instance).
72 d:add_text_input( text, ... ): Create an editable text field, in order to read user input.
73 d:add_password( text, ... ): Create an editable text field, in order to read user input. Text entered in this box will not be readable (replaced by asterisks).
74 d:add_check_box( text, state, ... ): Create a check box with a text. They have a boolean state (true/false).
75 d:add_dropdown( ... ): Create a drop-down widget. Only 1 element can be selected the same time.
76 d:add_list( ... ): Create a list widget. Allows multiple or empty selections.
77 d:add_image( path, ... ): Create an image label. path is a relative or absolute path to the image on the local computer.
79 Some functions can also be applied on widgets:
80 w:set_text( text ): Change text displayed by the widget. Applies to: button, label, html, text_input, password, check_box.
81 w:get_text(): Read text displayed by the widget. Returns a string. Applies to: button, label, html, text_input, password, check_box.
82 w:set_checked( bool ): Set check state of a check box. Applies to: check_box.
83 w:get_checked(): Read check state of a check box. Returns a boolean. Applies to: check_box.
84 w:add_value( text, id ): Add a value with identifier 'id' (integer) and text 'text'. It's always best to have unique identifiers. Applies to: drop_down.
85 w:get_value(): Return identifier of the selected item. Corresponds to the text value chosen by the user. Applies to: drop_down.
86 w:clear(): Clear a list or drop_down widget. After that, all values previously added are lost.
87 w:get_selection(): Retrieve a table representing the current selection. Keys are the ids, values are the texts associated. Applies to: list.
91 List of potential errors. It contains the following values:
92 .ENOENT: No such file or directory
94 .EACCESS: Permission denied
95 .EINVAL: Invalid argument
100 deactivate(): Deactivate current extension (after the end of the current function).
104 http( host, port, [cert, key, ca, crl]): create a new HTTP (SSL) daemon.
106 local h = vlc.httpd( "localhost", 8080 )
107 h:handler( url, user, password, callback, data ) -- add a handler for given url. If user and password are non nil, they will be used to authenticate connecting clients. callback will be called to handle connections. The callback function takes 7 arguments: data, url, request, type, in, addr, host. It returns the reply as a string.
108 h:file( url, mime, user, password, callback, data ) -- add a file for given url with given mime type. If user and password are non nil, they will be used to authenticate connecting clients. callback will be called to handle connections. The callback function takes 2 arguments: data and request. It returns the reply as a string.
109 h:redirect( url_dst, url_src ): Redirect all connections from url_src to url_dst.
113 input.is_playing(): Return true if input exists.
114 input.add_subtitle(url): Add a subtitle file (by path) to the current input
115 input.item(): Get the current input item. Input item methods are:
116 :uri(): Get item's URI.
117 :name(): Get item's name.
118 :duration(): Get item's duration in seconds or negative value if unavailable.
119 :is_preparsed(): Return true if meta data has been preparsed
120 :metas(): Get meta data as a table.
121 :set_meta(key, value): Set meta data.
122 :info(): Get the current input's info. Return value is a table of tables. Keys of the top level table are info category labels.
123 :stats(): Get statistics about the input. This is a table with the following fields:
144 All path for this namespace are expected to be passed as UTF8 strings.
146 io.mkdir("path", "mode"): Similar to mkdir(2). The mode is passed as a string
147 to allow for octal representations. This returns a success code (non 0 in
148 case of failure), and a more specific error code as its 2nd returned value
149 in case of failure. The error code is to be used with vlc.errno
150 io.readdir("path"): Lists all files & directories in the provided folder.
151 io.open("path"[, "mode"]): Similar to lua's io.open. Mode is optional and
152 defaults to "r". It returns a file object with the following member functions:
158 all of which are used exactly like the lua object returned by io.open
159 io.unlink("path"): Similar to os.remove. First return value is 0 in case
160 of success. In case of failure, the 2nd return parameter is an error
161 code to be compared against vlc.errno values.
165 msg.dbg( [str1, [str2, [...]]] ): Output debug messages (-vv).
166 msg.warn( [str1, [str2, [...]]] ): Output warning messages (-v).
167 msg.err( [str1, [str2, [...]]] ): Output error messages.
168 msg.info( [str1, [str2, [...]]] ): Output info messages.
170 Misc (Interfaces only)
171 ----------------------
172 ----------------------------------------------------------------
173 /!\ NB: this namespace is ONLY usable for interfaces.
175 ----------------------------------------------------------------
176 misc.version(): Get the VLC version string.
177 misc.copyright(): Get the VLC copyright statement.
178 misc.license(): Get the VLC license.
180 misc.action_id( name ): get the id of the given action.
182 misc.mdate(): Get the current date (in microseconds).
183 misc.mwait(): Wait for the given date (in microseconds).
185 misc.quit(): Quit VLC.
189 ----------------------------------------------------------------
190 /!\ NB: this namespace is ONLY usable for interfaces and extensions.
192 ----------------------------------------------------------------
193 net.url_parse( url ): Deprecated alias for strings.url_parse().
194 Will be removed in VLC 4.x.
195 net.listen_tcp( host, port ): Listen to TCP connections. This returns an
196 object with an accept and an fds method. accept is blocking (Poll on the
197 fds with the net.POLLIN flag if you want to be non blocking).
198 The fds method returns a list of fds you can call poll on before using
199 the accept method. For example:
200 local l = vlc.net.listen_tcp( "localhost", 1234 )
202 local fd = l:accept()
204 net.send( fd, "blabla" )
208 net.connect_tcp( host, port ): open a connection to the given host:port (TCP).
209 net.close( fd ): Close file descriptor.
210 net.send( fd, string, [length] ): Send data on fd.
211 net.recv( fd, [max length] ): Receive data from fd.
212 net.poll( { fd = events } ): Implement poll function.
213 Returns the numbers of file descriptors with a non 0 revent. The function
214 modifies the input table to { fd = revents }. See "man poll". This function
215 is not available on Windows.
216 net.POLLIN/POLLPRI/POLLOUT/POLLRDHUP/POLLERR/POLLHUP/POLLNVAL: poll event flags
217 net.read( fd, [max length] ): Read data from fd. This function is not
218 available on Windows.
219 net.write( fd, string, [length] ): Write data to fd. This function is not
220 available on Windows.
221 net.stat( path ): Stat a file. Returns a table with the following fields:
230 net.opendir( path ): List a directory's contents.
234 object.input(): Get the current input object.
235 object.playlist(): Get the playlist object.
236 object.libvlc(): Get the libvlc object.
237 object.aout(): Get the audio output object.
238 object.vout(): Get the video output object.
240 object.find( object, type, mode ): Return nil. DO NOT USE.
244 osd.icon( type, [id] ): Display an icon on the given OSD channel. Uses the
245 default channel is none is given. Icon types are: "pause", "play",
246 "speaker" and "mute".
247 osd.message( string, [id], [position], [duration] ): Display the text message on
248 the given OSD channel. Position types are: "center", "left", "right", "top",
249 "bottom", "top-left", "top-right", "bottom-left" or "bottom-right". The
250 duration is set in microseconds.
251 osd.slider( position, type, [id] ): Display slider. Position is an integer
252 from 0 to 100. Type can be "horizontal" or "vertical".
253 osd.channel_register(): Register a new OSD channel. Returns the channel id.
254 osd.channel_clear( id ): Clear OSD channel.
258 playlist.prev(): Play previous track.
259 playlist.next(): Play next track.
260 playlist.skip( n ): Skip n tracks.
261 playlist.play(): Play.
262 playlist.pause(): Pause.
263 playlist.stop(): Stop.
264 playlist.clear(): Clear the playlist.
265 playlist.repeat_( [status] ): Toggle item repeat or set to specified value.
266 playlist.loop( [status] ): Toggle playlist loop or set to specified value.
267 playlist.random( [status] ): Toggle playlist random or set to specified value.
268 playlist.goto( id ): Go to specified track.
269 playlist.add( ... ): Add a bunch of items to the playlist.
270 The playlist is a table of playlist items.
271 A playlist item has the following members:
272 .path: the item's full path / URL
273 .name: the item's name in playlist (OPTIONAL)
274 .title: the item's Title (OPTIONAL, meta data)
275 .artist: the item's Artist (OPTIONAL, meta data)
276 .genre: the item's Genre (OPTIONAL, meta data)
277 .copyright: the item's Copyright (OPTIONAL, meta data)
278 .album: the item's Album (OPTIONAL, meta data)
279 .tracknum: the item's Tracknum (OPTIONAL, meta data)
280 .description: the item's Description (OPTIONAL, meta data)
281 .rating: the item's Rating (OPTIONAL, meta data)
282 .date: the item's Date (OPTIONAL, meta data)
283 .setting: the item's Setting (OPTIONAL, meta data)
284 .url: the item's URL (OPTIONAL, meta data)
285 .language: the item's Language (OPTIONAL, meta data)
286 .nowplaying: the item's NowPlaying (OPTIONAL, meta data)
287 .publisher: the item's Publisher (OPTIONAL, meta data)
288 .encodedby: the item's EncodedBy (OPTIONAL, meta data)
289 .arturl: the item's ArtURL (OPTIONAL, meta data)
290 .trackid: the item's TrackID (OPTIONAL, meta data)
291 .options: a list of VLC options (OPTIONAL)
292 example: .options = { "run-time=60" }
293 .duration: stream duration in seconds (OPTIONAL)
294 .meta: custom meta data (OPTIONAL, meta data)
295 A .meta field is a table of custom meta key value pairs.
296 example: .meta = { ["GVP docid"] = "-5784010886294950089", ["GVP version] = "1.1", Hello = "World!" }
297 Invalid playlist items will be discarded by VLC.
298 playlist.enqueue( ... ): like playlist.add() except that track isn't played.
299 playlist.get( [what, [tree]] ): Get the playlist.
300 If "what" is a number, then this will return the corresponding playlist
301 item's playlist hierarchy. If it is "normal" or "playlist", it will
302 return the normal playlist. If it is "ml" or "media library", it will
303 return the media library. If it is "root" it will return the full playlist.
304 If it is a service discovery module's name, it will return that service
305 discovery's playlist. If it is any other string, it won't return anything.
306 Else it will return the full playlist.
307 The second argument, "tree", is optional. If set to true or unset, the
308 playlist will be returned in a tree layout. If set to false, the playlist
309 will be returned using the flat layout.
310 Each playlist item returned will have the following members:
311 .item: The input item.
313 .flags: a table with the following members if the corresponding flag is
319 .duration: (-1 if unknown)
321 .children: A table of children playlist items.
322 playlist.search( name ): filter the playlist items with the given string
323 playlist.current(): return the current playlist item id
324 playlist.sort( key ): sort the playlist according to the key.
325 Key must be one of the followings values: 'id', 'title', 'title nodes first',
326 'artist', 'genre', 'random', 'duration',
327 'title numeric' or 'album'.
328 playlist.status(): return the playlist status: 'stopped', 'playing', 'paused' or 'unknown'.
329 playlist.delete( id ): check if item of id is in playlist and delete it. returns -1 when invalid id.
330 playlist.move( id_item, id_where ): take id_item and if id_where has children, it put it as first children,
331 if id_where don't have children, id_item is put after id_where in same playlist. returns -1 when invalid ids.
333 FIXME: add methods to get an item's meta, options, es ...
338 Interfaces and extensions can use the following SD functions:
340 sd.get_services_names(): Get a table of all available service discovery
341 modules. The module name is used as key, the long name is used as value.
342 sd.add( name ): Add service discovery.
343 sd.remove( name ): Remove service discovery.
344 sd.is_loaded( name ): Check if service discovery is loaded.
346 Services discovery scripts can use the following SD functions:
348 sd.add_node( ... ): Add a node to the service discovery.
349 The node object has the following members:
350 .title: the node's name
351 .arturl: the node's ArtURL (OPTIONAL)
352 .category: the node's category (OPTIONAL)
353 sd.add_item( ... ): Add an item to the service discovery.
354 The item object has the same members as the one in playlist.add().
355 Returns the input item.
356 sd.remove_item( item ): remove the item.
358 n = vlc.sd.add_node( {title="Node"} )
359 n:add_subitem( ... ): Same as sd.add_item(), but as a child item of node n.
360 n:add_subnode( ... ): Same as sd.add_node(), but as a subnode of node n.
362 d = vlc.sd.add_item( ... ) Get an item object to perform following set operations on it:
363 d:set_name(): the item's name in playlist
364 d:set_title(): the item's Title (OPTIONAL, meta data)
365 d:set_artist(): the item's Artist (OPTIONAL, meta data)
366 d:set_genre(): the item's Genre (OPTIONAL, meta data)
367 d:set_copyright(): the item's Copyright (OPTIONAL, meta data)
368 d:set_album(): the item's Album (OPTIONAL, meta data)
369 d:set_tracknum(): the item's Tracknum (OPTIONAL, meta data)
370 d:set_description(): the item's Description (OPTIONAL, meta data)
371 d:set_rating(): the item's Rating (OPTIONAL, meta data)
372 d:set_date(): the item's Date (OPTIONAL, meta data)
373 d:set_setting(): the item's Setting (OPTIONAL, meta data)
374 d:set_url(): the item's URL (OPTIONAL, meta data)
375 d:set_language(): the item's Language (OPTIONAL, meta data)
376 d:set_nowplaying(): the item's NowPlaying (OPTIONAL, meta data)
377 d:set_publisher(): the item's Publisher (OPTIONAL, meta data)
378 d:set_encodedby(): the item's EncodedBy (OPTIONAL, meta data)
379 d:set_arturl(): the item's ArtURL (OPTIONAL, meta data)
380 d:set_trackid(): the item's TrackID (OPTIONAL, meta data)
384 stream( url ): Instantiate a stream object for specific url.
385 memory_stream( string ): Instantiate a stream object containing a specific string.
386 Those two functions return the stream object upon success and nil if an
387 error occurred, in that case, the second return value will be an error message.
389 s = vlc.stream( "http://www.videolan.org/" )
390 s:read( 128 ) -- read up to 128 characters. Return 0 if no more data is available (FIXME?).
391 s:readline() -- read a line. Return nil if EOF was reached.
392 s:addfilter() -- add a stream filter. If no argument was specified, try to add all automatic stream filters.
393 s:getsize() -- returns the size of the stream, or nil if unknown
394 s:seek(offset) -- seeks from offset bytes (from the begining of the stream). Returns nil in case of error
398 strings.decode_uri( [uri1, [uri2, [...]]] ): Decode a list of URIs. This
399 function returns as many variables as it had arguments.
400 strings.encode_uri_component( [uri1, [uri2, [...]]] ): Encode a list of URI
401 components. This function returns as many variables as it had arguments.
402 strings.make_uri( path, [scheme] ): Convert a file path to a URI.
403 strings.url_parse( url ): Parse URL. Returns a table with
404 fields "protocol", "username", "password", "host", "port", path" and
406 strings.resolve_xml_special_chars( [str1, [str2, [...]]] ): Resolve XML
407 special characters in a list of strings. This function returns as many
408 variables as it had arguments.
409 strings.convert_xml_special_chars( [str1, [str2, [...]]] ): Do the inverse
411 strings.from_charset( charset, str ): convert a string from a specified
412 character encoding into UTF-8; return an empty string on error.
416 var.inherit( object, name ): Find the variable "name"'s value inherited by
417 the object. If object is unset, the current module's object will be used.
418 var.get( object, name ): Get the object's variable "name"'s value.
419 var.get_list( object, name ): Get the object's variable "name"'s value list.
420 1st return value is the value list, 2nd return value is the text list.
421 var.set( object, name, value ): Set the object's variable "name" to "value".
422 var.create( object, name, value ): Create and set the object's variable "name"
423 to "value". Created vars can be of type float, string, bool or void.
424 For a void variable the value has to be 'nil'.
426 var.trigger_callback( object, name ): Trigger the callbacks associated with the
427 object's "name" variable.
429 var.libvlc_command( name, argument ): Issue libvlc's "name" command with
432 var.inc_integer( name ): Increment the given integer.
433 var.dec_integer( name ): Decrement the given integer.
434 var.count_choices( name ): Return the number of choices.
435 var.toggle_bool( name ): Toggle the given boolean.
439 video.fullscreen( [status] ):
440 * toggle fullscreen if no arguments are given
441 * switch to fullscreen 1st argument is true
442 * disable fullscreen if 1st argument is false
446 vlm(): Instanciate a VLM object.
449 v:execute_command( "new test broadcast" ) -- execute given VLM command
451 Note: if the VLM object is deleted and you were the last person to hold
452 a reference to it, all VLM items will be deleted.
456 volume.get(): Get volume.
457 volume.set( level ): Set volume to an absolute level between 0 and 1024.
459 volume.up( [n] ): Increment volume by n steps of 32. n defaults to 1.
460 volume.down( [n] ): Decrement volume by n steps of 32. n defaults to 1.
464 This module is only available on Windows builds
465 win.console_init(): Initialize the windows console.
466 win.console_wait([timeout]): Wait for input on the console for timeout ms.
467 Returns true if console input is available.
468 win.console_read(): Read input from the windows console. Note that polling and
469 reading from stdin does not work under windows.
473 xml = vlc.xml(): Create an xml object.
474 reader = xml:create_reader( stream ): create an xml reader that use the given stream.
475 reader:read(): read some data, return -1 on error, 0 on EOF, 1 on start of XML
476 element, 2 on end of XML element, 3 on text
477 reader:name(): name of the element
478 reader:value(): value of the element
479 reader:next_attr(): next attribute of the element
480 reader:node_empty(): queries whether the previous invocation of reader:read()
481 refers to an empty node ("<tag/>"). Returns a value less than 0 on error,
482 1 if the node is empty, and 0 if it is not.
484 The simplexml module can also be used to parse XML documents easily.